The research on network security concentrates mainly on securing the communication channels between two endpoints, which is insufficient if the authenticity of one of the endpoints cannot be determined with certainty. Previously presented methods that allow one endpoint, the authentication authority, to authenticate another remote machine. These methods are inadequate for modern machines that have multiple processors, introduce virtualization extensions, have a greater variety of side effects, and suffer from nondeterminism. This paper addresses the advances of modern machines with respect to the method presented by Kennell. The authors describe how a remote attestation procedure, involving a challenge, needs to be structured in order to provide correct attestation of a remote modern target system.